1. Field of the Invention
The invention relates to a tool head, in particular a precision boring head, having a machine shank and a tool shank which have a common mid-axis, the tool shank having a core and a head which is borne by a parallel spring arrangement that can be deflected resiliently in relation thereto and has a tool, in particular a head with a plurality of legs which originate from said head and form a parallel spring arrangement, of which at least one leg is fixed to the core or machine shank, and to a device for the radial adjustment of the head relative to the core.
2. Description of the Prior Art
A boring head of the generic type is disclosed by DE 33 32 243 A1. In this boring head, a spring-loaded, long pin with a head in the shape of a truncated cone is guided in the axial direction in its tool shank and can be adjusted in the axial direction. By means of axial displacement of the truncated cone-shaped pin which, for its part, presses against a bolt arranged in the head of the parallel spring arrangement, the tool in the head has impressed on it a slight radial movement corresponding to the pitch of the conical surface, and thus the tool is adjusted radially outward or inward. This device has been tried and tested in practice, but the tool head is relatively long and the tool-cutter holder is fixed in its position only by surface friction. In addition, this tool has very many parts and is therefore relatively expensive, and the tool must be implemented in cooperation with the machine manufacturer, because of the adjusting device being driven by signals from the machine. A further disadvantage resides in the fact that, because of the design, the coolant flows through the adjustment region of the setting device and therefore the setting device cannot always be set under the same conditions, because of contamination by coolant.
DE 39 26 026 A1 discloses a tool head of similar type, in which a parallel spring arrangement can be deflected resiliently against a base body. The tool is held in the parallel spring arrangement and can be adjusted radially by means of a device comprising a setting screw with a conical part, which bears with prestress against a complementary surface on the parallel spring arrangement. The disadvantage is that this device can be used only for a specific tool design, a long chisel, since, with this chisel, at the same time an imbalance compensating device is intended to be actuated in reverse, in order that highly accurate boring can be achieved with tools of this type. A further disadvantage consists in the fact that the tool cannot be preset and coolant flows through the setting region in which the setting screw is located, and through the imbalance compensating device.